1. Technical Field
The present invention pertains to the art of controlling exoskeleton systems, and more particularly, to a control system which is adapted to be coupled to a person.
2. Discussion of the Prior Art
Patients who have difficulty walking often use wheelchairs for mobility. It is a common and well-respected opinion in the field that postponing the use of wheelchairs will retard the onset of other types of secondary disabilities and diseases. The ramifications of long-term wheelchair use are secondary injuries including hip, knee, and ankle contractures, heterotopic ossification of lower extremity joints, frequent urinary tract infection, spasticity, and reduced heart and circulatory function. These injuries must be treated with hospital care, medications, and several surgical procedures. Physicians strongly advocate the idea that it is essential for patients to forgo the use of wheelchairs and remain upright and mobile as much as possible.
Functional Electrical Stimulation (FES) is primarily used to restore function in people with disabilities. FES is a technique that uses electrical currents to activate muscles in lower extremities affected by paralysis resulting from spinal cord injury (SCI), head injury, stroke and other neurological disorders. The patient wears a set of orthosis for stability. An electrical stimulator is always in the “off” mode except when the patient decides to walk. By triggering a mini-switch mounted on each handlebar of a rolling walker, the patient activates one or some of the quadriceps and hamstrings and muscles. The trigger signal from the switch is transmitted to the stimulator via a cable from the walker. The pulsed current is applied to the patient via conventional carbon-impregnated rubber electrodes covered with solid gel. The book titled “Functional Electrical Stimulation: Standing and Walking After Spinal Cord Injury”, Alojz R. Kralj, Tadej Bajd, CRC Press 1989, describes various technologies associated with FES. Another informative reference is “Current Status of Walking Orthoses for Thoracic Paraplegics”, published in The Iowa Orthopedic Journal by D'Ambrosia.
Another ambulation method uses powered exoskeleton systems. Most powered medical exoskeletons include interface devices that allows a user to command the exoskeleton, such that the user's decision on which leg to move and how to move it is reflected in the motion of the exoskeletons through them.
Currently, there are different types of user interface for commanding exoskeletons. For instance, U.S. Patent Application Publication No. 2011/0066088 A1, incorporated herein by reference, discloses an exoskeleton with a mechanically connected interface device that consists of a joystick and a keypad, which are used as a user input means to input control instructions to the exoskeleton's control system. Drawbacks of this device are that it is bulky and it requires the user's arm to be coupled with part of the exoskeleton. U.S. Pat. No. 7,153,242, incorporated herein by reference, discloses a gait-locomotor apparatus with a Man-Machine Interface through which a user controls modes of operation and parameters of the device, and receives various indications. However, each motion of the apparatus is triggered by a control unit, not directly by a user, based on measurements from various sensors. This limits the user's control capability of the apparatus, and requires a number of sensors to be installed on the apparatus.
Accordingly, a need remains in the art for a simpler, more versatile interface device for control of various exoskeletons. One solution is to exploit an instrumented glove as an interface device. Currently, instrumented gloves are used in various applications. For example, attempts to use such gloves as computer mice are described in U.S. Pat. Nos. 7,057,604 B2, and 6,154,199. Moreover, U.S. Pat. No. 6,681,638 B2, discloses an instrumented glove device that is adapted to wireless material handling systems.
Yet, no prior art instrumented glove type device has been designed for exoskeleton interface devices. Further, many such devices are user input devices with actuating mechanisms on the palm of a user's hand, which would be undesirable if a user were required to utilize the palm of the hand for another purpose, such as leaning on a cane or other balancing aid. The present invention discloses an interface device that is worn on a user's hand. Furthermore, in the present invention, the instrumented glove is reduced to finger sleeve type signal generators. This structure of the present invention minimizes the hindrance of a user's hand movement caused by the glove. Furthermore, the present invention maximizes a user's capability to control an exoskeleton, as well as provides feedback signals from the exoskeleton.